cas 9003-20-7, POLY(VINYL ACETATE) | Articles data

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Catalyst for acetylene method vinyl acetate synthesis
The invention relates to a catalyst for acetylene-method vinyl acetate synthesis and a preparation method thereof, and mainly solves the problem that by-product benzene content in the prior art is high. The catalyst comprises a carrier and an active component loaded on the carrier, wherein the active component comprises zinc acetate, and the carrier is activated carbon. The content of zinc acetate in the catalyst is 25 - 50g/L, the zinc acetate particle size is 3.0 - 5.0 nm, the problem is well solved, and the catalyst can be used in industrial production of acetylene-method vinyl acetate.
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Paragraph 0043-0245

(2021/11/10)

Catalytic Hydrogenation of Trivinyl Orthoacetate: Mechanisms Elucidated by Parahydrogen Induced Polarization
Parahydrogen (pH2) induced polarization (PHIP) is a unique method that is used in analytical chemistry to elucidate catalytic hydrogenation pathways and to increase the signal of small metabolites in MRI and NMR. PHIP is based on adding or exchanging at least one pH2 molecule with a target molecule. Thus, the spin order available for hyperpolarization is often limited to that of one pH2 molecule. To break this limit, we investigated the addition of multiple pH2 molecules to one precursor. We studied the feasibility of the simultaneous hydrogenation of three arms of trivinyl orthoacetate (TVOA) intending to obtain hyperpolarized acetate. It was found that semihydrogenated TVOA underwent a fast decomposition accompanied by several minor reactions including an exchange of geminal methylene protons of a vinyl ester with pH2. The study shows that multiple vinyl ester groups are not suitable for a fast and clean (without any side products) hydrogenation and hyperpolarization that is desired in biochemical applications.
Pravdivtsev, Andrey N.,Brahms, Arne,Kienitz, Stephan,S?nnichsen, Frank D.,H?vener, Jan-Bernd,Herges, Rainer
p. 370 - 377
(2021/02/09)

PROCESS TO PRODUCE ETHYLENE AND VINYL ACETATE MONOMER AND DERIVATIVES THEREOF
A method that includes (a) providing a stream containing ethane and oxygen to an ODH reactor; (b) converting a portion of the ethane to ethylene and acetic acid in the ODH reactor to provide a stream containing ethane, ethylene, acetic acid, oxygen and carbon monoxide; (c) separating a portion of the acetic acid from the stream to provide an acetic acid stream and a stream containing ethane, ethylene, oxygen and carbon monoxide; (d) providing the stream to a CO Oxidation Reactor containing a catalyst that includes a group 11 metal to convert carbon monoxide to carbon dioxide and reacting acetylene to produce a stream containing ethane, ethylene and carbon dioxide; and (e) providing a portion of the stream and a portion of the acetic acid stream to a third reactor containing a catalyst that includes a metal selected from group 10 and group 11 metals to produce vinyl acetate.
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Page/Page column 57-59

(2019/10/04)

Post-gilding of PD-AU-coated shell catalysts
The invention relates to a method for producing a shell catalyst that is suitable for producing vinyl acetate monomer (VAM). The invention further relates to a shell catalyst that is obtainable by the method according to the invention and to the use of the shell catalyst according to the invention for producing VAM.
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Page/Page column 16; 17

(2018/02/28)

HIGH PORE VOLUME ALUMINA SUPPORTED CATALYST FOR VINYL ACETATE MONOMER (VAM) PROCESS
Disclosed is a supported catalyst for the preparation of vinyl acetate monomer (VAM), a process for preparing a catalyst comprising an extruded alumina support, and a catalytic process for the manufacturing vinyl acetate using the supported catalyst. Specifically, it is shown that for activated palladium-gold VAM catalysts prepared using extruded alumina supports, enhanced performance is demonstrated with increased pore volume of the support, and the gas hourly space velocity (GHSV, hr?1), which was found to significantly increase the space time yield as GHSV increased as compared to the non-extruded alumina supported catalysts.
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Paragraph 0082-0084

(2018/05/26)

Nanostructured Pd?Cu Catalysts Supported on Zr?Al and Zr?Ti for Synthesis of Vinyl Acetate
Renewable ethylene can be obtained by dehydration of bio-ethanol and used for production of vinyl acetate (VAM) through reaction with acetic acid (AcOH), using Pd?Cu catalysts. In the present manuscript, structural characterizations of Pd?Cu/ZrO2 catalysts show that these systems present cubic structure with different spatial distributions. Particularly, it is shown that combustion of ethylene and acetic acid can be inhibited below 180 °C, maximizing the rates of VAM formation, when the catalysts are modified with Ti+4. The effects of AcOH concentration on rates of VAM formation show that higher AcOH concentrations favor the formation of undesired byproducts, while lower AcOH concentrations favor effects related to O2 mobility, which can lead to surface decomposition. VAM formation is favored, with selectivities ranging from 0.8 to 1.0. XPS results indicate the existence of metallic Pd, CuO species and Zr species, in agreement with IR results. DRIFTS results also show that different Pd-acetate intermediates can be present, depending on the electronic effects associated to Pd?Cu and Zr species.
Gonzalez Caranton, Alberth Renne,Dille, Jean,Barreto, Jade,Stavale, Fernando,Pinto, José Carlos,Schmal, Martin
p. 5256 - 5269
(2018/11/10)

HIGH GEOMETRIC SURFACE AREA CATALYSTS FOR VINYL ACETATE MONOMER PRODUCTION
A catalyst includes a support, where the support includes an external surface, about 60 wt% to about 99 wt% silica, and about 1.0 wt% to about 5.0 wt% alumina. A catalytic layer is disposed within the support adjacent to the external surface, where the catalytic layer further includes Pd, Au, and potassium acetate (KOAc). In the catalyst, (a) the KOAc is from about 60 kg/m3 to about 150 kg/m3 of the catalyst; or (b) the catalytic layer has an average thickness from about 50 μm to about 150 μm; or (c) both (a) and (b). The catalyst also possesses a Brunauer-Emmett-Teller surface area of about 130 m2/g to about 300 m2/g and a geometric surface area per packed bed volume from about 550 m2/m3 to about 1500 m2/m3. The catalyst is highly active for the synthesis of vinyl acetate monomer and exhibits a high selectivity for vinyl acetate monomer.
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Paragraph 0050

(2017/02/09)

By preparing vinyl acetate ethylene diacetate cracking method
The invention relates to a method for preparing vinyl acetate (VAC) from ethylidene diacetate (EDA) through pyrolysis. The method mainly comprises the following step: in the presence of a catalyst, performing thermal pyrolysis on EDA so as to obtain VAC. The method is characterized in that the catalyst is aluminum trichloride modified macropore styrene cation exchange resin, and aluminum trichloride accounts for 0.1-3.0wt% of the total weight of the catalyst. When VAC is prepared by using the method provided by the invention, not only is the VAC easily separated from the catalyst, but also the conversion rate of EDA can be increased, and the selectivity of VAC can be relatively greatly improved.
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Paragraph 0009; 0019; 0020; 0021; 0022-0027

(2017/04/28)

PROCESS FOR THE PREPARATION OF VINYL ACETATE
A process for the preparation of vinyl acetate by a heterogeneously catalysed, continuous gas-phase reaction of ethylene, acetic acid and oxygen in a reactor, where process heat liberated during the reaction is removed from the reactor by means of heat exchange with water, generating intrinsic steam, the product mixture leaving the reactor and comprising ethylene, vinyl acetate, acetic acid, water, carbon dioxide and inert gases is separated by distillation using one or more azeotrope columns and/or one or more pure distillation columns, wherein at least one azeotrope column and/or pure distillation column contains packings, and intrinsic steam is used at least partially for introducing energy into the thus-equipped azeotrope columns and/or pure distillation columns.
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Paragraph 0048

(2016/03/13)

ELECTROLESS DEPOSITION OF AU-PD BIMETALLIC CATALYSTS FOR ALKENYL ACETATE PRODUCTION
The present invention relates to a process for the preparation of a Au-Pd bimetallic shell-type catalyst, comprising the following steps: a. providing a solid, shaped body catalyst support, b. contacting the support with two solutions, one solution containing Au ions in an amount of from 0.1-10 wt% and the other solution containing Pd ions in an amount of from 0.1-10 wt%, with the proviso that the weight ratio of Pd:Au is in the range of from 0.2:1 to 4:1. c. reducing the plated support with hydrogen to obtain the Au-Pd bimetallic shell-type pre-catalyst, d. contacting the Au-Pd bimetallic pre-catalyst with an aqueous potassium acetate solution with a content of potassium in the range of from 0.1-10 wt%, e. drying to obtain the Au-Pd bimetallic shell-type catalyst. The invention further relates to a process for the production of alkenyl acetates, applying the Au-Pd bimetallic catalyst.
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Page/Page column 16

(2016/12/26)

Method for the production of vinyl acetate
The present invention relates to a method for producing vinyl acetate. Provided in the present invention is a method for producing vinyl acetate by gas phase oxidization of ethylene, comprising: an optional step of preparing ethylene, a step of synthesizing vinyl acetate, and a step of refining vinyl acetate, wherein in at least one of the step of preparing ethylene, the step of synthesizing vinyl acetate and the step of refining vinyl acetate, at least one of a steam machine recompression technique, an air cooler, a plate heat exchanger, and a double shell pass tube-and-shell heat exchanger is used.
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Paragraph 0058-0066

(2017/03/14)

Method of synthesizing vinyl acetate from methyl acetate
The invention relates to a method of synthesizing vinyl acetate from methyl acetate and mainly solves the problem of low yield and low selectivity of the vinyl acetate when methyl acetate is successively subjected to carbonylation and pyrolysis to prepare the vinyl acetate. In the technical scheme, the method mainly includes the following steps: 1) carbonylating the methyl acetate to obtain ethylidene diacetate; and 2) pyrolyzing the ethylidene diacetate to obtain the vinyl acetate. A carbonylation catalyst includes a main catalyst and a co-catalyst, wherein the main catalyst includes a carrier and an active component, a rhodium compound being the active component, and the co-catalyst is an iodide, and the carrier is silicon dioxide which is modified by a fluorine compound and has a coating on the surface. The coating is composed of modified metal elements, and silicon dioxide adhesive which is used for bonding the modified metal elements to the surface of the carrier, wherein the modified metal elements is at least one selected from IIA metal elements.
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Paragraph 0136; 0137; 0138; 0139; 0140; 0141

(2016/12/16)

Synthetic method for vinyl acetate
The invention relates to a synthetic method for vinyl acetate and is mainly to solve the problems of low yield and selectivity of vinyl acetate in preparation for vinyl acetate from methyl acetate successively through carbonylation and cracking routes. According to a technical scheme of the invention, the synthetic method for vinyl acetate comprises the following steps: subjecting methyl acetate to carbonylation so as to obtain ethylidene diacetate, and subjecting ethylidene diacetate to cracking so as to obtain vinyl acetate, wherein a carbonylation catalyst uses SiO2, Al2O3 or a mixture of SiO2 and Al2O3 as a carrier; an active component is at least one selected from the group consisting of platinum-cluster metals, at least one selected from the group consisting of group-VIB metals, and at least one selected from the group consisting of group-IB metals and lanthanide series metals; thus, the above-mentioned technical problems are well solved, and the synthetic method can be applied in industrial production of vinyl acetate.
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Paragraph 0174; 0175; 0176; 0177; 0178

(2016/12/16)

Production method of vinyl acetate
The invention relates to a production method of vinyl acetate and mainly solves the problems of low yield and low selectivity of the vinyl acetate when methyl acetate is successively subjected to carbonylation and pyrolysis to prepare the vinyl acetate. The production method includes the following steps: 1) carbonylating the methyl acetate to obtain ethylidene diacetate; and 2) pyrolyzing the ethylidene diacetate to obtain the vinyl acetate. A carbonylation catalyst includes a carrier being formed from SiO2, Al2O3 or a mixture of them, and an active component including at least one of platinum-series elements, at least one element from metalloid elements, and at least one metal element from the groups of IIB and lanthanide-series metals. The method solves the technical problems well and can be used in industrial production of the vinyl acetate.
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Paragraph 0175; 0176; 0177; 0178; 0179

(2016/12/16)

Method of preparing vinyl acetate from methyl acetate
The invention relates to a method of preparing vinyl acetate from methyl acetate and mainly solves the problems of low yield and low selectivity of the vinyl acetate when methyl acetate is successively subjected to carbonylation and pyrolysis to prepare the vinyl acetate. In the technical scheme, the method mainly includes the following steps: 1) carbonylating the methyl acetate to obtain ethylidene diacetate; and 2) pyrolyzing the ethylidene diacetate to obtain the vinyl acetate. A carbonylation catalyst includes a main catalyst and a co-catalyst, wherein the main catalyst includes a carrier and an active component, a rhodium compound being the active component, and the co-catalyst is an iodide, and the carrier is silicon dioxide which is modified by modifying metal elements and has an aluminum coating on the surface. The content of aluminum is 1.00-10.00 g/L, the content of the modifying metal elements is 0.010-1.00 g/L, and the modifying metal elements include at least one metal element in the IVB group.
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Paragraph 0157; 0158; 0159; 0160; 0161; 0162

(2016/12/16)

For method for producing vinyl acetate (by machine translation)
The invention relates to a method for method for producing vinyl acetate, methyl acetate, mainly solves the carbonylation, when the cracking line preparing vinyl acetate ethylene acetate of the problem of low yield and selectivity. By using for the method for producing vinyl acetate, comprising the following steps: obtaining of carbonylation of methyl acetate-ethylene carbonate acetate; double-acetate ethylene acetate esters an ethylene cracking obtained; the the catalyst states the carbonylation SiO 2, Al 2 O 3 or mixtures thereof as a carrier, is selected from the active component comprises at least one of iron series elements, lanthanides, and IIB and alkaline earth metal selected from at least one of the technical scheme of the metal elements, better solves the technical problem of, can be used in the industrial production of ethylene acetate. (by machine translation)
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Paragraph 0182; 0183; 0184; 0185; 0186; 0187

(2016/12/16)

Method for producing vinyl acetate through methyl acetate carbonylation
The invention relates to a method for producing vinyl acetate through methyl acetate carbonylation. When vinyl acetate is prepared from methyl acetate through the route of carbonylation and cracking, vinyl acetate yield and selectivity are low. The invention mainly aims at solving the problems. The method comprises the following steps: methyl acetate carbonylation is carried out, such that ethylene diacetate is obtained; and ethylene diacetate is cracked, such that vinyl acetate is obtained. A carbonylation catalyst adopts SiO2, Al2O3 or a mixture thereof as a carrier, and has active components comprising at least one selected from platinum-group elements, at least one selected from alkaline earth metals and at least one metal element selected from IVA and lanthanide-series metal elements. With the technical scheme, the technical problem is well solved. The method can be used in industrial production of vinyl acetate.
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Paragraph 0170; 0172; 0173; 0174; 0175; 0176; 0177

(2016/12/16)

Method for preparing vinyl acetate
The invention relates to a method for preparing vinyl acetate. The method mainly solves the problem that the prior art for preparing vinyl acetate through methyl acetate carbonylation and carboxide cracking has a low yield and low selectivity. The method provided through the invention comprises methyl acetate carbonylation for ethylidene diacetate preparation and ethylidene diacetate cracking for vinyl acetate preparation. A carbonylation catalyst utilizes SiO2, Al2O3 or their mixture as a carrier and active ingredients comprise rhodium and at least one of cerium, strontium and tin. The method well solves the technical problem and can be used for vinyl acetate industrial production.
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Paragraph 0112; 0118; 0119

(2016/12/01)

Method for synthesis of vinyl acetate through hydroformylation of methyl acetate
The invention relates to a method for synthesis of vinyl acetate through hydroformylation of methyl acetate. The method mainly solves the problem that the existing vinyl acetate preparation method utilizing methyl acetate carbonylation and carboxide cracking has a low yield and low selectivity. The method provided through the invention comprises methyl acetate carbonylation for ethylidene diacetate preparation and ethylidene diacetate cracking for vinyl acetate preparation. A carbonylation catalyst utilizes SiO2, Al2O3 or their mixture as a carrier and active ingredients comprise at least one of iron group metal elements, at least one of IIIB elements and at least one of VA and alkaline earth metals. The method well solves the technical problem and can be used for vinyl acetate industrial production.
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Paragraph 0161; 0163; 0164; 0165; 0169

(2016/12/01)

Method of producing vinyl acetate from methyl acetate through hydroformylation
The invention relates to a method of producing vinyl acetate from methyl acetate through hydroformylation and mainly solves the problems of low yield and low selectivity of the vinyl acetate when methyl acetate is successively subjected to carbonylation and pyrolysis to prepare the vinyl acetate. The method herein includes the following steps: 1) carbonylating the methyl acetate to obtain ethylidene diacetate; and 2) pyrolyzing the ethylidene diacetate to obtain the vinyl acetate. A carbonylation catalyst includes a carrier being formed from SiO2, Al2O3 or a mixture of them, and an active component including at least one of iron-series elements, at least one element from metalloid elements, and at least one metal element selected from the groups of IIB and alkali metals. The method solves the technical problems well and can be used in industrial production of the vinyl acetate.
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Paragraph 0173; 0174; 0175; 0176; 0177

(2016/12/16)

Method for synthesizing vinyl acetate
The invention relates to a method for synthesizing vinyl acetate. When vinyl acetate is prepared from methyl acetate through the route of carbonylation and cracking, vinyl acetate yield and selectivity are low. The invention mainly aims at solving the problems. The vinyl acetate synthesis method comprises the following steps: methyl acetate carbonylation is carried out, such that ethylene diacetate is obtained; and ethylene diacetate is cracked, such that vinyl acetate is obtained. A carbonylation catalyst adopts SiO2, Al2O3 or a mixture thereof as a carrier, and has active components comprising at least one selected from iron-series elements, alkaline earth metal and at least one metal element selected from IB and VA. With the technical scheme, the technical problem is well solved. The method can be used in industrial production of vinyl acetate.
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Paragraph 0151; 0152; 0153; 0154; 0155

(2016/12/16)

Method for synthesis of vinyl acetate
The invention relates to a method for synthesis of vinyl acetate. The method mainly solves the problem that the existing vinyl acetate preparation method utilizing methyl acetate carbonylation and carboxide cracking has a low yield and low selectivity. The method provided through the invention comprises methyl acetate carbonylation for ethylidene diacetate preparation and ethylidene diacetate cracking for vinyl acetate preparation. A carbonylation catalyst comprises a carrier and rhodium, copper, lanthanum and lithium on the carrier. The carrier is at least one of silicon oxide and alumina. The method well solves the technical problem and can be used for vinyl acetate industrial production.
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Paragraph 0131; 0133; 0135; 0136; 0137

(2016/12/16)

Method for synthesizing vinyl acetate through methyl acetate carbonylation
The invention relates to a method for synthesizing vinyl acetate through methyl acetate carbonylation. When vinyl acetate is prepared from methyl acetate through the route of carbonylation and cracking, vinyl acetate yield and selectivity are low. The invention mainly aims at solving the problems. The method comprises the following steps: methyl acetate carbonylation is carried out, such that ethylene diacetate is obtained; and ethylene diacetate is cracked, such that vinyl acetate is obtained. A carbonylation catalyst adopts SiO2, Al2O3 or a mixture thereof as a carrier, and has active components comprising at least one selected from iron-series elements, at least one selected from metalloid elements and at least one metal element selected from IB and alkaline earth metals. With the technical scheme, the technical problem is well solved. The method can be used in industrial production of vinyl acetate.
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Paragraph 0166; 0167; 0168; 0169; ;0170; 0171

(2016/12/16)

Zinc acetate immobilized on mesoporous materials by acetate ionic liquids as catalysts for vinyl acetate synthesis
Ionic liquid containing active ingredient Zn(CH3COO)2 was loaded in mesoporous silica gel to form supported ionic liquids catalyst (SILC) which was used to synthesize vinyl acetate monomer (VAM). SILC was characterized by 1HNMR, FT-IR, TGA, BET, and N2 adsorption/desorption and the acetylene method was used to evaluate SILC catalytic activity and stability in fixed reactor. The result shows that 1-allyl-3-acetic ether imidazole acetate ionic liquid is successfully fixed within mesoporous channel of silica gel. The average thickness of ionic liquid catalyst layer is about 1.05 nm. When the catalytic temperature is 195°C, the acetic acid (HAc) conversion is 10.9% with 1.1 g vinyl acetate yield and 98% vinyl acetate (VAc) selectivity. The HAc conversion is increased by rise of catalytic temperature and molar ratio of C2H2: HAc and decreased by mass space velocity (WHSV). The catalyst activity is not significantly reduced within 7 days and VAc selectivity has a slight decrease.
Xu, Hang,Yu, Tianlong,Li, Mei
(2015/04/14)

Nanosized {Pd4(μ4-C)}Pd32(CO)28(PMe3)14 Containing Tetrahedrally Deformed Pd4 Cage with Encapsulated Carbide Atom: Formal Substitution of Geometrically Analogous Interior Au4 Entity in Isostructural Au4Pd32(CO)28(PMe3)14 by Electronically Equivalent Pd4(μ4-C) and Computational/Catalytic Implications
This first homopalladium carbido cluster, {Pd04(μ4-C)}Pd32(CO)28(PMe3)14 (1), was isolated (3-7% yields) from an ultimately simplified procedure - the reaction of CHCl3 under N2 with either Pd8(CO)8(PMe3)7 or Pd10(CO)12(PMe3)6 at room temperature. Charge-coupled device (CCD) X-ray diffraction data at 100 K for 1·2.5 C6H14 (1a) and 1·3 CHCl3 (1b) produced closely related molecular parameters for 1. This {Pd4C}Pd32 cluster (1) possesses a highly unusual tetracoordinated carbide atom that causes a major distortion of a central regular Pd4 tetrahedron into a new symmetry type of encapsulated Pd4 cage of pseudo-D2 (222) symmetry. Mean Pd-Pd distances for the three pairs of opposite twofold-equivalent Pd-Pd tetrahedral-like edges for 1a are 2.71, 2.96, and 3.59 ?; the mean of the four Pd-C distances [range, 1.87(2)-1.94(2) ?] is 1.91 ?. An astonishing molecular feature is that this {Pd4C}Pd32 cluster (1) is an isostructural and electronically equivalent analogue of the nanosized Au4Pd32(CO)28(PMe3)14 (2). Cluster 2, likewise a pseudo-D2 molecule, contains a geometrically analogous tetrahedrally deformed interior Au4 entity encapsulated within an identical Pd32(CO)28(PMe3)14 shell; mean distances for the three corresponding symmetry-equivalent pairs of slightly smaller opposite tetrahedral-distorted Au-Au edges are 2.64, 2.90, and 3.51 ?. A computational study by both a natural population analysis (NPA) and an atoms-in-molecules (AIM) method performed on model analogues {Pd4C}Pd32(CO)28(PH3)14 (1-mod) and Au4Pd32(CO)28(PH3)14 (2-mod) suggested that the negatively charged Au4 entity in 2-mod may be described as two weakly interacting electron-pair Au2 intradimers. In contrast, an NPA of the {Pd4C} entity in 1-mod revealed that two similarly oriented identical Pd2 intradimers of 2.71 ? are primarily stabilized by Pd-C bonding with a negatively charged carbide atom. The isostructural stabilizations of 1 and 2 are then attributed to the similar sizes, shapes, and overall negative charge distributions of the electronically equivalent interior {Pd4C} and Au4 entities. This resulting remarkable structural/electronic equivalency between 1 and 2 is consistent with the greatly improved performances of commercial palladium catalysts for vinyl acetate synthesis by gold-atom incorporation to suppress carbonization of the Pd atoms, namely, that the extra Au 6s1 valence electron of each added Au atom provides an effective "negative charge protection" against electron-donating carbon atoms forming Pd carbido species such as {Pd4C}. (Figure Presented).
Mednikov, Evgueni G.,Ivanov, Sergei A.,Dahl, Lawrence F.
p. 6157 - 6168
(2015/07/15)

Method And Catalyst Composite For Production Of Vinyl Acetate Monomer
Provided are catalyst composites useful for the production of vinyl acetate monomer, as well as methods of making using same. The catalyst composites may comprise a support comprising silica and about 1 to about 3 wt-% alumina, wherein the support has a surface area of about 175 to about 300 m2/g; and an eggshell layer on the support comprising Pd and Au.
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Paragraph 0051-0061

(2014/02/16)

COPPER-PROMOTED SHELL CATALYST FOR PRODUCING ALKENYL CARBOXYLIC ACID ESTERS
A method for producing a shell catalyst which is suitable for the synthesis of alkenyl carboxylic acid esters, in particular for producing vinyl acetate monomer (VAM) from ethylene or allyl acetate monomer from propylene by means of oxy-acetylation. Also, a shell catalyst that can be obtained by the method according to the invention, as well as the use of the shell catalyst produced using the method for producing alkenyl carboxylic acid esters, in particular vinyl acetate monomer (VAM) and allyl acetate monomer.
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Paragraph 0116-0117

(2014/04/03)

Dendrimer-stabilized bimetallic Pd/Au nanoparticles: Preparation, characterization and application to vinyl acetate synthesis
The preparation, characterization and a novel application to vinyl acetate synthesis of dendrimer-stabilized Pd/Au nanoparticles are described. The nanoparticles were synthesized by co-precipitation of aqueous Pd 2 +/Au3 + salt solutions with hydrazine in the presence of (poly)amidoamine (PAMAM)-based dendrimers functionalized with terminal ethylene glycol ethers. Characterization by transmission electron microscopy and UV-vis spectroscopy confirmed that alloyed Pd/Au nanoparticles with a mean diameter of 6.0 (± 1.2) to 10.4 (± 1.7) nm were formed. After nanoparticle immobilization onto a silica support and thermal dendrimer removal, the resulting materials are high active catalysts in ethylene acetoxylation to vinyl acetate monomer with a productivity of 2.1 kgVAM kg cat- 1 h- 1.
Kuhn, Martin,Jeschke, Janine,Schulze, Steffen,Hietschold, Michael,Lang, Heinrich,Schwarz, Thomas
p. 78 - 82
(2014/10/16)

Process and Apparatus for Preparing Vinyl Acetate Monomer
The invention provides a process for preparing vinyl acetate monomer (VAM) by reacting ethylene with acetic acid and oxygen in a tube bundle reactor in a heterogeneously catalysed, continuous gas phase process, characterized in that a high-performance catalyst with a space-time yield of more than 700 g of VAM/l of catalyst×hour is used for catalysis, and in that the tube bundle reactor comprises tubes with a ratio of inner surface area to volume of ≧130 m-1.
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Page/Page column 2-9

(2012/03/08)

Visible-light-mediated α-arylation of enol acetates using aryl diazonium salts
Visible light mediates efficiently the α-arylation of enol acetates by aryl diazonium salts under mild conditions using [Ru(bpy)3]Cl 2 as a photoredox catalyst. The broad scope of the reaction toward various diazonium salts and enol acetates was explored. The application of this reaction in the concise synthesis of 2-substituted indoles was demonstrated
Hering, Thea,Hari, Durga Prasad,Koenig, Burkhard
p. 10347 - 10352
(2013/01/15)

Monoatomically dispersed Pd/TiO2 catalyst effective for epoxidation of propylene at ambient temperature in the presence of H2 and O2
The catalytic activity of monoatomically dispersed Pd supported on TiO 2 toward propylene epoxidation in the presence of H2 and O2 was studied at ambient temperature, and both propylene oxide (PO) and propane were obtained. Short-chain alkanes also reacted but epoxide formation was not observed in those reactions except in the case of isobutane, which formed isobutylene oxide at a low rate. The optimum surface concentration of Pd on TiO2 was 0.005-0.01 atom/nm2; because the supported amount of Pd is extremely small relative to the surface area of the support, the supported Pd is thought to be monoatomically dispersed. Pd/TiO 2 catalysts prepared from a tetraphenylporphyrin-Pd chloride complex showed almost the same product distribution for propylene epoxidation as did catalysts prepared from Pd(NO3)2. Isotope exchange between H2 and D2 proceeded over Pd/TiO2 with a low surface concentration (0.0001 atom-Pd/nm2), and chemical potential calculations suggested that H2 molecules could dissociatively adsorb onto the monoatomically dispersed Pd/TiO2. A PO formation mechanism over the catalyst is proposed on the basis of these results. The results presented here may provide the first clear evidence of catalysis by monoatomically dispersed noble metals.
Hikazudani, Susumu,Mochida, Tatsuya,Matsuo, Naofumi,Nagaoka, Katsutoshi,Ishihara, Tatsumi,Kobayashi, Hisayoshi,Takita, Yusaku
body text
p. 89 - 98
(2012/06/18)

Effect of acetate promotor on the Pd-Au/SiO2-catalyzed synthesis of vinyl acetate from the reaction of ethylene with acetic acid
The effect of Group I alkali acetate promoters on vinyl acetate (VA) synthesis was evaluated. Catalyst product selectivity and ethylene conversion are compared to the unpromoted catalyst in the fixed-bed reactor with oxidation reaction of ethylene and acetic acid in gaseous phase over Pd-Au/SiO2 catalyst. It was found that: a) the promoters were stabilized on the catalyst surface, b) common effect for the alkali promoted Pd-Au catalysts increaseed in product selectivity and ethylene conversion compared to unpromoted catalyst (these effects increase from top to the bottom of Group I). These promoting effect is due to the common-ion effect of acetate, present in the reaction, resulting in an increase in the activity of the catalyst. In addition a complementary theory for the effect of Au in the structure of the catalyst is proposed the imposition of distribution of palladium particles through decreasing the particle's diameter.
Atashi, Hossein,Motahari, Kazem,Tabrizi, Farshad Farshchi,Sarkari, Majid,Fazlollahi, Farhad
experimental part
p. 92 - 97
(2011/04/18)

PROCESS FOR THE PRODUCTION OF ACETIC ACID ETHYLENE AND VINYL ACETATE MONOMER
An integrated process for the production of acetic acid, ethylene and vinyl acetate monomer comprising the steps of: (a) evaporating at least part of an ethanol feed stock(b) producing in a first reaction zone a first product stream comprising acetic acid by oxidative or partly oxidative dehydrogenation of ethanol feed stock;(c) producing in a second reaction zone a second product stream comprising ethylene from an ethanol feed stock;(d) reacting in a third reaction zone an acetic acid reaction stream containing at least a portion of the acetic acid from the first reaction zone with an ethylene reaction stream containing at least a portion of the ethylene product from the second reaction zone and with oxygen to a third product stream comprising vinyl acetate monomer;(e) passing at least a portion of the third product stream to a distillation section and isolating at least a portion of the vinyl acetate monomer;(f) supplying at least part of reaction heat from the third reaction zone to provide heat for evaporating at least part of the ethanol feed stock in step (a);(g) supplying at least part of reaction heat from the first reaction zone to provide heat for producing the second product stream in the second reaction zone in step (c) and for distilling of the third product stream in the distillation section in step (e).
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Page/Page column 3

(2011/06/24)

Preparation of palladium-gold catalyst
A method for preparing a palladium-gold catalyst containing a titania extrudate is disclosed. The titania extrudate is produced by using a carboxyalkyl cellulose and a hydroxyalkyl cellulose as extrusion aids. The titania extrudate has improved processibility and/or mechanical properties. After calcination, the extrudate is used as a carrier for the palladium-gold catalyst. The catalyst is useful in producing vinyl acetate by oxidizing ethylene with oxygen in the presence of acetic acid.
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Page/Page column 5

(2011/06/26)

Vinyl acetate formation in the reaction of acetylene with acetic acid catalyzed by zinc acetate supported on porous carbon spheres
A kind of porous carbon spheres (PCS) was prepared by the carbonization of poly(vinylidene chloride) synthesized by suspension polymerization. Structure analyses revealed the existence of bumps and holes on the surface of PCS. The PCS, with the pore size between 0.8-1.2 nm, could be used as the support of zinc acetate because of the regular shape, high specific surface area, and good mechanical strength. Vinyl acetate was produced from acetylene and acetic acid using the PCS-supported zinc acetate (PCS-Zn) under mild conditions. In a single-pass operation performed at 220°C, the conversions of acetic acid and acetylene reached 22.6 and 5.3% respectively while the activity of vinyl acetate formation was above 1000 g mol-1 h-1.
Yan, Feng-Wen,Guo, Cun-Yue,Yan, Fang,Li, Feng-Bo,Qian, Qing-Li,Yuan, Guo-Qing
experimental part
p. 796 - 801
(2010/08/05)

ACYLOXYLATION CATALYST AND PROCESS FOR ITS PRODUCTION
An acyloxylation catalyst is obtained by loading (a) a first component containing at least one element of Groups 8, 9, 10 and 11 of the Periodic Table, (b) a second component containing an element which is at least one element of Groups 8, 9, 10 and 11 of the Periodic Table and which is different from the element of the first component, and (c) a third component containing an element which is a component that produces a precipitation-starting pH below the precipitation-starting pH of the first component and second component and which is different from the elements of the first component and second component, onto (d) a support. A catalyst is obtained that can be used to efficiently carry out acyloxylation for economical production of acyloxylated compounds.
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(2010/04/23)

Coverage effects on the palladium-catalyzed synthesis of vinyl acetate: Comparison between theory and experiment
The high adsorbate coverages that form on the surfaces of many heterogeneous catalysts under steady-state conditions can significantly lower the activation energies for reactions that involve the coupling of two adsorbed intermediates while increasing those which result in adsorbate bond-breaking reactions. The influence of the surface coverage on the kinetics of metal-catalyzed reactions is often ignored in theoretical and even in some ultrahigh vacuum experimental studies. Herein, first principle density functional theoretical calculations are combined with experimental surface titration studies carried out over well-defined Pd(111) surfaces to explicitly examine the influence of coverage on the acetoxylation of ethylene to form vinyl acetate over Pd. The activation energies calculated for elementary steps in the Samanos and Moiseev pathways for vinyl acetate synthesis carried out on acetate-saturated palladium surfaces reveal that the reaction proceeds via the Samanos mechanism which is consistent with experimental results carried out on acetate-saturated Pd(111) surfaces. The rate-limiting step involves a β3-hydride elimination from the adsorbed acetoxyethyl intermediate, which proceeds with an apparent calculated activation barrier of 53 kJ/mol which is in very good agreement with the experimental barrier of 55 ± 4 kJ/mol determined from kinetic measurements.
Calaza, Florencia,Stacchiola, Dario,Neurock, Matthew,Tysoe, Wilfred T.
experimental part
p. 2202 - 2207
(2010/04/28)

Integrated process for the production of vinyl acetate from acetic acid via ethylene
This invention provides an integrated two stage economical process for the production of vinyl acetate monomer (VAM) from acetic acid in the vapor phase. First, acetic acid is selectively hydrogenated over a hydrogenating catalyst composition to form ethylene either in a single reactor zone or in a dual rector zone wherein the intermediate hydrogenated products are either dehydrated and/or cracked to form ethylene. In a subsequent second stage so formed ethylene is reacted with molecular oxygen and acetic acid over a suitable catalyst to form VAM. In an embodiment of this invention reaction of acetic acid and hydrogen over a hydrogenation catalyst and subsequent reaction over a dehydration catalyst selectively produces ethylene, which is further mixed with acetic acid and molecular oxygen and reacted over a supported palladium/gold/potassium catalyst
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Page/Page column 9-10

(2010/06/13)

Supported palladium-gold catalysts and preparation of vinyl acetate therewith
Disclosed is a catalyst. The catalyst comprises palladium, gold, and a support comprising titanium dioxide and tungsten trioxide. The support preferably comprises from 75 wt % to 99 wt % of titanium dioxide and from 1 wt % to 25 wt % of tungsten trioxide. A method for preparing the catalyst is also disclosed. The method comprises impregnating the support with a palladium compound and a gold compound, calcining the impregnated support, and then reducing the calcined support. Further disclosed is a method for preparing vinyl acetate with the catalyst. The catalyst exhibits improved catalytic activity and selectivity.
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Page/Page column 2-3

(2010/06/11)

PROCESS FOR PRODUCTION OF CATALYST FOR ALKENYL ACETATE PRODUCTION
A catalyst is produced by a process that comprises at least a step of impregnating a carrier with an alkali solution having a mass of greater than 0.9 times and no greater than 1.0 times the amount of water absorption of the carrier, a step of further impregnating the carrier by contact with a solution A comprising at least a compound containing palladium or platinum and a compound containing a Group 11 element, a step of reduction treatment and a step of loading an acetic acid salt on the carrier, wherein the carrier is first impregnated with the alkali solution and then the contacted with solution A to form a catalyst precursor, and wherein the total amount of the alkali solution and solution A is a mass of at least 1.1 times and no greater than 10.0 times the amount of water absorption of the carrier. A catalyst for alkenyl acetate production is obtained that exhibits improved activity and selectivity.
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Page/Page column 9

(2010/07/08)

Integrated process for the production of viny acetate from acetic acid via ethy acetate
This invention provides an integrated three step economical process for the production of vinyl acetate monomer (VAM) from acetic acid in the vapor phase. First, acetic acid is selectively hydrogenated over a hydrogenating catalyst composition to form ethyl acetate which is cracked to form ethylene and acetic acid in the second step and in a subsequent step so formed ethylene and acetic acid is reacted with molecular oxygen over a suitable catalyst to form VAM. In an embodiment of this invention reaction of acetic acid and hydrogen over platinum and copper supported on silica selectively produces ethyl acetate in a vapor phase at a temperature of about 250° C., which is cracked over a NAFION catalyst to form ethylene and acetic acid at a temperature of about 185° C., which is mixed with molecular oxygen and reacted over a palladium/gold/potassium catalyst supported on titania to form VAM at a temperature of about 150° C. to 170° C.
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Page/Page column 14

(2010/09/08)

Kinetic parameters for the elementary steps in the palladium-catalyzed synthesis of vinyl acetate
The kinetics of the reaction between gas-phase ethylene and adsorbed acetate species to form vinyl acetate monomer (VAM) on a Pd(111) surface are measured using infrared spectroscopy to monitor the rate of acetate removal, as well as the rates of VAM and ethylidyne formation, at various temperatures. The results are fit using a kinetic model first proposed by Samanos in which ethylene reacts with acetate species to form an acetoxyethyl intermediate that forms VAM via β-hydride elimination. The results of the kinetic model agree well with the experimental data and Arrhenius plots of the rate constants yield activation energies that are in good agreement with those predicted by density functional theory (DFT) calculations. DFT also predicts that the reaction activation energies should depend on the acetate coverage while the experimental data can be fit by constant values of the rate constants, suggesting that the reaction activation energies are similar for a reaction center surrounded either by acetate species, ethylidynes, or a combination of both. Finally, the kinetic parameters for VAM desorption are in good agreement with the experimental peak temperature measured by temperature-programmed desorption for VAM desorbing from an ethylidyne-covered surface.
Calaza, Florencia,Stacchiola, Dario,Neurock, Matthew,Tysoe, Wilfred T.
experimental part
p. 135 - 142
(2011/01/04)

Pyrolysis of α- and β-heteroatoms substituted ethyl phenyl sulfoxides
A study on the mechanism of the thermal decomposition of α- and β-heteroatoms substituted ethyl phenyl sulfoxides was carried out using 1-chloroethyl phenyl sulfoxide (1); two diastereomeric 1-acetoxyethyl (substituted phenyl) sulfoxides (2a) and (2b); and 2-chloroethyl phenyl, 2-bromoethyl phenyl, and 2-methoxyethyl phenyl sulfoxides (3, 4, 5). The rate of pyrolysis of 1 was 4.8 times faster at 160°C than that of ethyl phenyl sulfoxide used as a reference, while those of 2a and 2b were 107 and 155 times faster, respectively. The results indicate that the lone pair of electrons on the α-heteroatoms has a larger rate acceleration effect than the electronegativity of them. The substituent effects of the phenyl group of 2a and 2b gave positive Hammett ρ-values (ρa= 0.76 and ρb= 0.80 vs. σ). Activation parameters for 2a and 2b are as follows: 2a, ΔH?= 112 kJmol-1, ΔS?= -20 JK-1mol-1; 2b, ΔH?= 107 kJmol-1, ΔS?= -29 JK-1mol-1. Large deuterium kinetic isotope effects for 1-acetoxyethyl-2,2,2-d3 phenyl sulfoxides (2ad and 2bd) were observed (kH/kD= 3.5 ～ 4.1). These results suggest that the pyrolysis of -heteroatom substituted ethyl phenyl sulfoxides proceeds via a five-membered transition state deviated to E1-like in character. On the other hand, from the results of kinetics for the pyrolysis of 3, 4, and 5, no effect by the β-halogen atoms or some deceleration effect by the β-methoxy group was observed. Thus the reaction seems to proceed via an E1-like mechanism. Copyright Taylor & Francis Group.
Yoshimura, Toshiaki,Sakae, Hironori,Yoshizawa, Masaki,Hasegawa, Kiyoshi,Tsukurimichi, Eiichi
experimental part
p. 1162 - 1173
(2010/08/06)

Pd(II)-catalyzed hydroxyl-directed C-H olefination enabled by monoprotected amino acid ligands
A novel Pd(II)-catalyzed ortho-C-H olefination protocol has been developed using spatially remote, unprotected tertiary, secondary, and primary alcohols as the directing groups. Mono-N-protected amino acid ligands were found to promote the reaction, and an array of olefin coupling partners could be used. When electron-deficient alkenes were used, the resulting olefinated intermediates underwent subsequent Pd(II)-catalyzed oxidative intramolecular cyclization to give the corresponding pyran products, which could be converted into ortho-alkylated alcohols under hydrogenolysis conditions. The mechanistic details of the oxidative cyclization step are discussed and situated in the context of the overall catalytic cycle.
Lu, Yi,Wang, Dong-Hui,Engle, Keary M.,Yu, Jin-Quan
scheme or table
p. 5916 - 5921
(2010/07/05)

Highly efficient dynamic kinetic resolution of secondary aromatic alcohols with low-cost and easily available acid resins as racemization catalysts
A new and efficient dynamic kinetic resolution (DKR) process of secondary aromatic alcohols was developed with acid resins as racemization catalysts. Acid resin CD8604 was shown to have excellent racemization activity and good biocompatibility. When employing CD8604 and complex acyl donors as racemization catalyst and acyl donor, respectively, enantiomerically pure aromatic acetate was obtained with excellent yield and ee values through the DKR process. It is noteworthy that the system could be reused more than 10 times with little loss of yield and ee value.
Cheng, Yongmei,Xu, Gang,Wu, Jianping,Zhang, Chensheng,Yang, Lirong
supporting information; experimental part
p. 2366 - 2369
(2010/06/13)

Integrated process for the production of vinyl acetate from acetic acid via acetaldehyde
This invention provides an integrated multistep economical process for the production of vinyl acetate monomer (VAM) from acetic acid in the vapor phase. First, acetic acid is selectively hydrogenated over a hydrogenating catalyst composition to form acetaldehyde. Acetaldehyde so formed can be converted to ethylidene diacetate via reaction with acetic anhydride. In a subsequent step so formed ethylidene diacetate is thermally decomposed to form VAM and acetic acid. Alternatively, acetaldehyde formed in the first step can selectively be reacted with ketene to form VAM. In an embodiment of this invention reaction of acetic acid and hydrogen over platinum and iron supported on silica selectively produces acetaldehyde in a vapor phase at a temperature of about 300° C., which is selectively hydrogenated over platinum supported catalyst to form ethanol and dehydrated over NAFION catalyst to form ethylene at a temperature of about 185° C., which is mixed with molecular oxygen, acetic acid and reacted over a palladium/gold/potassium catalyst supported on titania to form VAM at a temperature of about 150° C. to 170° C.
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Page/Page column 12

(2010/07/08)

CATALYST
Catalyst comprising palladium, gold and alkali metal acetate as catalytically active components on a support, which is modified by means of titanium, iron, lanthanum, cerium, yttrium and/or molybdenum or oxides thereof. It can be used for preparing vinyl acetate monomer.
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Page/Page column 1-2

(2009/04/24)

USE OF VINYL ACETATE-SULFONATE COPOLYMERS AS SOLUBILIZERS FOR SLIGHTLY WATER-SOLUBABLE COMPOUNDS
The use of copolymers obtainable by free radical-initiated copolymerization of a) 80 to 99.5% by weight of vinyl acetate andb) 0.5 to 20% by weight of a monoolefinically unsaturated monomer having sulfonate groups as solubilizers for slightly water-soluble substances.
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(2009/10/21)

Process for Preparing Vinyl Acetate with Utilization of the Heat Reaction
Vinyl acetate is prepared by a) continuous gas-phase reaction of ethylene, acetic acid and oxygen at 1 to 30 bar and 130° C. to 200° C., the process heat being removed by heat exchange with water at 120° C. to 185° C. and 1 to 10 bar, b) the product gas stream consisting essentially of ethylene, vinyl acetate, acetic acid, water, carbon dioxide and further inert gases is fractionated, and c) all or part of the ethylene is recycled to the recycle gas process, wherein all or part of steam formed in the gas-phase reaction by heat exchange, with a temperature of from 120° C. to 185° C. and pressure of from 1 to 10 bar, is compressed by a differential pressure of at least 0.5 bar and used further.
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Page/Page column 3

(2008/12/07)

Preparation of palladium-gold catalysts
A method for preparing supported palladium-gold catalysts is disclosed. The method comprises increasing the porosity of a titanium dioxide support, impregnating the support with a palladium salt, a gold salt, and an optional alkali metal or ammonium compound, and reducing the calcined support. The resultant supported palladium-gold catalysts have increased activity in the acetoxylation.
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(2008/12/08)